Key features of the case study
During the last decades of the 20th century, the Danube Delta has suffered from human interventions that led to dramatic changes in some areas. These interventions consisted in the dyking of large areas for the purpose of agricultural use, intensive fish-farming and forestry, which resulted in dramatic alterations or disturbances of the water balance. This had effects on the alteration of natural processes, the ecological balance as well as the characteristic functions of wetlands and led to a deterioration, or worse the loss of area-specific habitats. When the transformation measures were stopped in early 1990, the dyked area covered 97.408 ha (22 %) of the total 482.592 ha, including Babina polder(2100 ha), designed to be a rice polder but abandoned before to be fully built. Studies for rehabilitation/restoration measures were started in the Danube Delta immediately following its declaration as Biosphere Reserve in 1990.
The objective of ecological reconstruction/restoration was to restore the natural, site-specific hydrological, biogeochemical and ecological functions, to ensure the redevelopment of the ecosystem and its functions and thus to promote the development of site-specific habitats and their biodiversity. Moreover, the redevelopment of the natural resources should enable the local populations to proceed to their sustainable, traditional use. Given that the ecosystems of the Danube Delta depend on the dynamics of the Danube River, the re-establishment of the hydrological regime reveals to be the most important factor to be considered in restoration. In the case of dyked and drained polders that are no longer useful for agricultural purposes, the reconnection to the flood regime of the Danube is the measure to be taken and the prerequisite for a successful restoration.
The chosen measures do not restore the original conditions of the time before the dyking, given that this would require a complete removal of the dams, which again reveals impossible in view of extremely high costs so, the opening of the dams in specific hydrological and ecologically effective spots and the reconnection to the river dynamics could restore a better performance of the ecosystem.
The implementation of the measures ensured a redevelopment of the site-specific biodiversity and resources. It caused a change of mind and offered new incentives to restore further flood areas that had been altered by man, in the Danube Delta but also beyond.
The monitoring conducted over 10 years accounts for a relatively rapid development of the area, the hydrological regime with its fluctuating floods and dry periods representing the key factor for restoration. Flood conditions do, however, differ from the natural flood situation. Before the construction of the dams, i.e. under natural conditions, it occurred with a large-scale overflooding of the island. In the case of the dyked Babina island it merely occurs in the area of the dam openings. Despite of these constraints the efficiency of the ecosystem has been reestablished by an opening of the dams in specific hydraulically and ecologically effective spots and the reconnection to the river dynamics.
Monitoring before and after implementation of the project
A monitoring programme was elaborated and implemented so as to find answers to all major issues regarding restoration, to document the development subsequent to the re-flooding and to verify the success of the measures taken. This allowed to show development trends, evaluate the measures and, if required, to propose further corrective supplementary measures. First results as for the restoration of hydrological, biogeochemical and ecological functions have been published in 1997 in a comprehensive report elaborated in co-operation with the Danube Delta National Institute for Research and Development in Tulcea, Romania, and WWF Germany’s Institute for Floodplain Ecology, Rastatt (recently integrated as chair in the Institute for Water and River Basin Management, University of Karlsruhe).
Contact person within the organization
Mircea Staras, scientific director, firstname.lastname@example.org
Marian Tudor, scientist, email@example.com
Extra background information
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Rezultate preliminare privind instalarea ornitofaunei tipic acvatice în ostrovul cernovca după inundare Sesiunea jubiliară a Universităţii Bacău. Universitatea Bacău, Bacău. 6. Marin, G., Mitache V., Tudor M., Hulea D., Păun A., Baboianu C., Schneider E., Schneider Ec., Gunther-Diringer D., Obrdlik P., Rast G., W eller P.,. 1997. Ecological restoration in the danube delta biosphere reserve/romania ed. ICPDD/Umweltstiftung WWF-Deutschland. 7. Marin, G., Schneider E., Păun A., Mitache V., Tudor M., Hulea D.,. 1996. Refacerea funcţiilor şi valorilor ecologice în condiţii de reconstrucţie ecologică a polderelor agricole - studiu de caz babina. Analele stiintifice ale Institutului de Cercetare şi Proiectare Delta Dunării 5: 105-109. 8. Navodaru I., M. Staras., A.D. Buijse, J. De Leeuw, 2005. Changes in fish populations in Danube delta lakes: effects of hydrology and water quality change. Review of results and potential for rehabilitation, Ecohydrology&Hydrobiology, vol.5, No 3, 245-256. 9. Schneider, E., Tudor, M., Staraş, M. (Editor), 2008. Evolution of babina polder after restoration works. Ecological restoration in the danube delta biosphere reserve/romania. Kraft-Druck Ettlingen, 80 pp. 10. Staraş, M. 1998. Fishery in relation with environment in the danube delta biosphere reserve. In: N. J. Nijland (ed.) Proccedings of the symposium "Dealing with nature in deltas", riza, lelzstad, the netherlands. p 157-168. 11. Staras, M. 2001. Restoration programme in the Danube Delta: achievements, benefits and constraints, In: H.L.Nijland (ed.), Proceedings of the symposium “River restoration in Europe”, RIZA, Lelystad, The Netherlands, 95-101 12. Staraş, M., Corhan, Gh., Daneş M., Cernişencu I., Năvodaru I., Grigoraş I., . 1996. Pachet de programe pe calculator pentru estimarea stocurilor de peşti. . Analele ştiinţifice ale INDD, Tulcea, 2: 339-343. 13. Ştiucă, R., Staraş M., Tudor M.,. 2002. The ecological restoration in the danube delta. An alternative for sustainable management of degraded wetlands. Published for IAD by the Limnological Commission of the Romanian Academy. Limnological reports. Proceedings of the 34 Conference, Tulcea, Romania 2002 34: 707-721. 14. Torok, L. 2001. Ecological status of babina reconstructed area after 9 years of rehabilitation. Scientific Annals of the Danube Delta Institute for Research and Development, Tulcea-Romania 8: 171-178. 15. Tudor, I.-M. 2005. The diversity of zooplanckton in two restored wetlands in the danube delta. In kotowski w. Ed, anthropogenic influence on wetlands biodiversity and sustainable management of wetlands. Warsaw Agricultural University Press: 145-157. 16. Tudor, I.-M. 2008. Evolution of zooplankton diversity. Schneider E., Tudor M., Staras M. Eds, Evolution of Babina polder after restoration works Germany: Kraft-Druck Ettlingen. 17. Tudor, M. 2002. Evolution of zooplankton diversity in babina polder between 1997 and 2001. Scientific Annals of the Danube Delta Institute for research and development.ed Tehnica 9: 196-205. 18. Tudor, M., Cioacă E., Hulea O., Marinov M., Mitache V., Moldovan M., Trache G., Schneider E., Obrdlik P., Schneider Ec., Gunther-Diringer D., Lagendijk O., Menting G., Posthoorn R., . 2000b. Perspectives on popina. Recomandations for ecological restoration and wise use of former fishponds in the danube delta biosphere reserve/romania. RIZA werkdocument 2000.137X. 19. Tudor, M., Cioacă, E., Mitache, V. 1999. Reconstrucţia ecologică a incintelor abandonate din rezervaţia biosferei "Delta dunării". Principii şi obiective. Reconstrucţia ecologică a râurilor. Compania Naţională "Apele Române", Bucureşti. 20. Tudor, M., Dumitraşcu, M. 2006. Acţiuni de reconstrucţie ecologică. In: P. Gâştescu, Ştiucă, R. (ed.) Delta dunării rezervaţie a biosferei. p 451-455. Editura Dobrogea, Constanţa. 21. Tudor, M., Hulea, D., Marin, G. 1996. Vegetation and its ecological functions in the danube delta restored polders Sesiunea jubiliară a Universităţii Bacău. Universitatea Bacău, Bacău. 22. Zinevici, V., Teodorescu (Parpală) L.,. 1994. Caracteristicile structurale ale planctonului ecotonal din delta dunării în condiţii diferenţiate de restaurare ecologică (zona rusca) şi impact antropic (ostroavele Babina şi Cernovca). Analele stiintifice ale Institutului de Cercetare şi Proiectare Delta Dunării: 281-286.